Nikita Karetnikov <nik...@karetnikov.org> writes:
> I'm attaching a patch.
>
> It's a separate file; if I add these lines
>
> #:use-module (guix packages)
> #:use-module (guix store)
>
> to 'guix/build/utils.scm', they will raise the following error on
> 'make'.
Based on the backtrace below, it looks like you tried to add those to
guix/utils.scm, not guix/build/utils.scm. It failed because it resulted
in a circular dependency between modules.
(guix utils) -> (guix packages) -> (guix derivations) -> (guix utils)
Circular dependencies are not always fatal in Guile, but they can be
when one of the modules depends on a *macro* from another module in the
cycle. In this case, (guix derivations) uses the 'memoize' macro from
(guix utils).
[Adds to Guile TODO list: better error messages in cases like this]
> Also, 'bin-location' and 'chmod' are not safe. It can be solved with
> 'file-exists?'
I don't know what the issue is here (and don't have time now to figure
it out), but the idea that 'file-exists?' can make anything safe is
setting off warning bells in my head, because it sounds like a
TOCTTOU[1] race condition: someone else may change the filesystem
between your 'file-exists?' check and whatever you do that depends on
that check for safety.
Regards,
Mark
[1] http://en.wikipedia.org/wiki/Time-of-check-to-time-of-use
